T2 SOMETHING ABOUT SEEDS. 
by the spiral twisting which characterizes many similar fibres. 
The evident design of the plumes, as in other cases where seeds 
are provided with such appendages, is to assist in the wide-spread 
distribution of the species. Many seeds probably fall quite near 
the parent plant, but chance breezes carry others often to a very 
great distance. 
Some one is already wondering, doubtless, why I have not taken 
the more familiar dandelion for illustration. It is simply because, 
as I have said, the Asclepias happened to be upon my table. As 
every one knows, the dandelion (Taraxacum), the groundsel (Sene- 
cio), the thistle (Cirsium and Onopordon), and many other genera 
of Composit, the willows (Salicaceæ), some of the buttercups 
(Ranunculacez), the evening primrose family (Onagracez), to- 
gether with members of many other orders, are similarly endowed 
with silky tufts to assist the seed in its migrations. The exe- 
cution may differ in diverse species, but the plan remains the ~ 
same. This is the commonest, yet other methods are adopted to 
obtain the same end, as we notice in the key-like samara of the 
maple and the winged seeds of the trumpet creeper (Tecoma radi- 
cans), of the pines and the elms. All these are charming objects 
viewed by the unassisted eye, or more closely examined by means 
of the microscope. 
I cannot dismiss this portion of my subject without dwelling 
for a few moments upon the means provided for the scattering of 
seeds. Some plants, like the balsam (Impatiens) and the gera- 
nium, by a sudden contraction of portions of the capsule, expel 
the contents with a jerk, which often throws them to a consider- 
able distance. Others are provided with little hooks, claws, fine 
Hħirs, or some other mechanical means of attaching themselves to — 
moving objects and availing themselves of their involuntary aid. 
There is no American botanist, probably, but has expostulated 
mildly with the chain-like pods of Desmodium, which will persist ` 
in adhering to one’s clothing, and the removal of which is no 
small task. The barbed achenium of Bidens frondosa is another 
pest to man, as are the burs of Lappa major, or burdock, to sheep 
and cattle, but we must bear in mind that in the case of these 
plants, we are merely mediums of conveyance, and have tempo- 
rarily resigned our proud position at the head of nature. 
Animals and birds often distribute seeds which have passed 
through the system undigested ; currents of water in the ocean 
